In 1237, having conquered much of the Central Asian steppes, a massive force of Mongols led by the third generation of Chinggis Khan’s descendants launched a campaign into eastern Europe, taking Kiev (1240) and sweeping westward into Poland and Hungary. News of this invasion quickly reached as far west as England. After more than 130 years of crusading, Latin Christians were passably familiar with the political and cultural complexities of the eastern Mediterranean; knowledge of the lands farther east, however, remained a hazy blend of ancient authors, Biblical lore, the Alexander Romance, and the legend of Prester John. Within short order, however, western European leaders took the initiative in their own hands, dispatching exploratory missions to the Mongols, like those of the Franciscans John of Plano Carpini in the mid-1240s and William of Rubruck in the early 1250s. Thanks to the detailed accounts of their travels they wrote on their return, the Mongols emerged from the fog of apocalyptic terror that had first surrounded them and, like a gradually-developing Polaroid, took on the contours of people with their own history, customs, and institutions